Cameron, who wrote and sang the the Scotland football team’s 1978 World Cup anthem Ally’s Tartan Army, joined him outside the city’s Gallery of Modern Art.

The 73-year-old comedian said: “I’m a passionate Scotsman, I love Scotland, but I also believe under the umbrella of the United Kingdom we’re a stronger country.”

He added: “We don’t need to stand up and say we’re independent, the world knows who we are, they know it was a Scotsman who invented the telephone, that it was a Scotsman who discovered penicillin, it was a Scotsman who invented television. We are a powerful nation, we’ve contributed so much to this planet we live in.

“But that doesn’t mean to say we need to divorce ourselves from the UK.”

Cameron said he had joined Mr Murphy as “just another supporter” and added: “The Yes campaign has a lot of the ‘we hate England’ attitude. I was born in London, my mother was English, my father was Scottish.

“We’ve lived together through two world wars, and I think we’ve got to stick together now.”

Mr Murphy said he and Cameron had “been pals for years”, adding that he had become the first celebrity to join him on his speaking tour after the comedian phoned and offered his help.